In a video system which utilizes a solid state sensor to generate image signals for color monitor and NTSC video applications, timing must be provided so that the first pixel to be displayed out of the imaging sensor is synchronized with the start of the first picture line of the color monitor raster or NTSC video raster. The timing is complicated by the fact that the signal out of the sensor is usually subject to downstream processing prior to reaching the monitor or NTSC encoder. This intermediate signal processing delays the signal from reaching the monitor and encoder, and must be compensated for by the system timing in order to achieve a proper video display.
In addition, it may also be desirable to synchronize (genlock) the video system to an external video source such as a separate video camera. This requires the synchronization of the sensor, monitor and encoder to the external video source, while maintaining the aforementioned delay compensation between the sensor and the monitor or encoder.
Conventionally a system for adjusting the timing of a video output from a camera or playback device so as to be synchronous with another video source is described in U.S. Pat. No. 3,984,633 by Rutt et al.